1. Field of the Invention
The present invention relates to a method and apparatus for transmitting data and a method and apparatus for performing a task, and more particularly, to a method and apparatus for transmitting data for process migration and a method and apparatus for performing a migrated process.
2. Description of the Related Art
Data processing speed in computers (or processors) has gradually increased; however, further improvements in this regard are limited. Accordingly, a distribution system has been introduced as an alternative to further increase data processing speed. A plurality of computers interconnected through a network form a distribution system. Since data processing is executed by the plurality of computers in the distribution system, data processing speed is increased considerably.
Process migration is one technique used in the distribution system in order to transmit a process performed in a source device to a target device. When the process migration technique is used, a part of a task to be performed by an overloaded computer is performed by a less-loaded computer so that dynamic load balancing can be efficiently accomplished in the computers of the distribution system.
However, in the conventional art, when two or more processes are to migrate to a target device, the process migration order has not yet been determined so that a process to be performed firstly is sometimes performed later. Moreover, when only one process is to migrate, which data from among data needed to migrate the process should be firstly transmitted has not been yet determined so that a target device can perform the process only after all data is transmitted.
Meanwhile, according to the latest developments in information and communication technologies, the number of users who use more than two spatially separated computers has increased. An example will be given when one computer is used at work and another computer is used at home and a user moves to a different place while he/she performs a process using a computer at work. When performing another task using the processes performed or results obtained by performing the process is not urgent, problems may not occur. In this case, the user may move to a different place while the computer is turned on so as to perform the process automatically or the user may move to a different place after the performing of the task is temporarily stopped. However, when performing another task using the processes performed or the results obtained by performing the process is urgent, the above described case may not be applied. In this case, when the process currently performing is moved to the computer at home using a process migration technique, the process can be continuously performed using the computer at home.
As such, a process migration technique can be applied not only to a distribution system but also to spatially separated computers.
However, when the conventional process migration technique is applied to the distribution system, a network connection between the source device and the target device should be stable, otherwise the process migration cannot be performed.
Thus, as an alternative, a method of storing data needed for process migration from the source device in a mobile storage medium and transmitting the stored data to the target device has been proposed. However, when the storage capacity of the mobile storage medium is not sufficient, data to be written has not yet been determined so that data cannot be transmitted or data must be sequentially written, regardless of the importance. Moreover, even in an urgent case, for example, when a user cannot wait for the data to be transmitted, all data should be written and thus a data transmission time increases.